摘要
The surface properties of fluorite are often affected by dissolved gangue species(e.g.,calcite)during the flotation process.Microflotation testing with and without the addition of calcite supernatant was conducted using octanohydroxamic acid(OHA)as the collector.The results revealed that dissolved calcite species significantly affected the flotation behavior of fluorite.Fourier transform infrared spectra confirmed that the decrease in flotation recovery was linked to lower OHA adsorption.Solution chemistry analysis indicated that CaCO_(3) and Ca^(2+)from the calcite supernatant were the most favorably adsorbed species,and X-ray photoelectron spectroscopy analysis confirmed the surface adsorption of calcite species.Density functional theory simulations provided a detailed analysis of the multidentate adsorption configuration of OHA,which was the most favorable for adsorption on the fluorite surface.The adsorption energy calculation showed that the calcite dissolved species were more stably adsorbed on the fluorite surface than OHA.The pre-adsorption of calcite dissolved species hindered the adsorption of OHA due to electrostatic repulsion.
在浮选过程中,萤石的表面性质经常会受到溶解脉石组分(例如:方解石)的影响。采用OHA作为捕收剂,对有无方解石上清液时进行微浮选测试。研究表明,溶解的方解石组分明显影响萤石的浮选行为。FTIR测试证明,浮选回收率的下降与OHA吸附降低有关。溶液化学分析结果表明,方解石上清液中的CaCO_(3)和Ca^(2+)是最有可能被吸附的组分。同时,XPS分析也证实方解石物种在萤石表面的吸附。DFT模拟计算提供对OHA的多齿吸附构型的详细分析,该构型是OHA在萤石表面吸附的最佳构型。计算出的吸附能表明,与OHA相比,方解石溶解物更稳定地吸附在萤石表面,而预吸附的方解石溶解组分会通过静电排斥作用阻碍OHA的吸附。
基金
The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.51874247,51922091,51904249)
Young Elite Scientists Sponsorship Program by CAST,China(No.2018QNRC001)
Sichuan Science and Technology Program,China(Nos.2019YFS0453,2018JY0148)
Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,China(No.CNMRCUKF2001)
Postgraduate Innovation Fund by Southwest University of Science and Technology,China(No.20ycx0027).
